Pump



July 11, 1967 J. w. BAUR ETAL 3,330,217

PUMP

Filed July 20, 1965 5 1 i. 7 105 92 fg 55 a! d E j five/722K; @fwam m aw /awfiggcww United States Patent 3,330,217 PUMP John W. Baur, lenview,and Walter M. J ones, Evanston,

Ill., assiguors to Biuks Manufacturing Company, Chicago, Ill., acorporation of Delaware Filed July 20, 1965, Ser. No. 473,349 2 Claims.(Cl. 103-168) The present invention relates to pumps, particularly to apump of improved construction facilitating fabrication of pumps forcorrosive and abrasive liquids, such as polyurethanes containing methylethyl hydroxide, and other materials of a highly corrosive and/orabrasive character.

A primary object of the invention is to provide a pump in which thepiston is mounted in limited spaced relation to the cylinder walls bymeans of readily replaceable packings, whereby to minimize machining ofthe piston and cylinder and thereby to facilitate formation of thepiston and the cylinder of commercially available materials highlyresistant to corrosion and abrasion.

Another object of the invention is to provide an improved pump in whichthe piston and cylinder are unitized members without valves or portswhereby further to facilitate their formation of corrosion and abrasionresistant materials.

A further object of the invention is the provision of a pump which mayreadily be disassembled for repair and replacement of its constituentparts, including the piston and the cylinder.

A still further object of the invention is the provision of a pump forcorrosive and/ or abrasive liquids in which the piston is formed ofceramic material and in which means are provided for maintaining theceramic material under compression.

These other objects of the invention will become apparent from thefollowing detailed description.

Now, in order to acquaint those skilled in the art with the manner ofmaking and using our improved pump, we shall describe, in connectionwith the accompanying drawings, preferred embodiments of the pump andpreferred manners of making and using the same.

In the drawings, wherein like reference numerals indicate like parts;

FIGURE 1 is a vertical sectional view of a pump made in accordance withthe present invention showing the piston in its down position;

FIGURE 2 is a plan view of the pump of FIGURE 1; and

FIGURE 3 is a vertical sectional view of a second embodiment of the pumpshowing the piston thereof in raised or up position.

Referring now to the drawings, and particularly to FIGURE 1, ourimproved pump is characterized by a relatively simple piston assemblyand a cylinder and valve assembly 11. The assembly 11 comprises a pairof tubular members defining the pump cylinder 14, and a pair ofsimplified valve structures defining an inlet valve 16 and a by-passvalve 18.

According to an important feature of the present invention, the cylinder14 comprises a first or upper section 26, preferably formed from squarebar stock, having a central bore and provided adjacent its lower endwith a downwardly facing interior shoulder 28 and interior threads 30,and a second or lower section 32 having, at the upper end thereof,external threads 34 for engagement with the threads of the section 26.The upper annular edge of the section 32 supports a ring 35 having anupwardly facing annular recess of V cross-section, and a plurality ofchevron packing glands or rings 36 are received in the V. The section 32may be threaded into 3,330,217 Patented July 11, 1957 the section 26 tourge the rings 36 upwardly into abutment with a ring 40, the bottomsurface of which is of V shape in cross-section conformably to receivethe chevron packing. The ring 40 is in turn abutted against the shoulder28 and thus the rings 36 are compressed as the section 32 is tightenedinto the section 26, the compressive force thus applied resulting inradially inward extension of the rings 36 for sealed engagement with thepiston 10. Rotation of the section 32, if formed from tube stock, isfacilitated by a spanner ring 42 having circumferentially spaced holestherein for reception of a spanner Wrench. It will be appreciated thatthe packing rings 36 may be taken up from time to time, as required, inresponse to wear. A combined seal and lock nut 44 is threaded on thethreads 34 and engaged with the bottom of section 26 to lock the twosections in adjusted position.

The upper end of the upper section 26 is provided with a bore 58accommodating slidable passage of the pump piston, the bore being formedwith an upwardly open counterbore 60 provided with internal threads 64for threaded reception of a plug or gland nut 66 having a central bore68. The bottom edge of the nut 66 is formed with an annular recess of Vcross-section for reception of chevron packing rings 70, the bottom-mostone of which rests on a metal support ring 72 whose upper surface is ofV cross-section and whose bottom surface rests on shoulder 62 definedbetween bore 58 and counterbore 60. The plug 66 thus forms take-up meansfor the sealing rings 70 to cause the same to seal about the piston 10,in much the same manner as the sealing rings 36.

The upper section 26 is further formed with a radial port 54 immediatelybelow the upper seal 70, and a pair of radial ports 86 and 88immediately above and below the sealing means 36. The upper port 54comprises the pump outlet, the same preferably being threaded forreception of an outlet fitting, and the ports 86 and 88 together withthe valve 18 comprise a bypass between the two sections of the cylinder.

The valve 18 comprises a valve block 90 suitably secured to the fiatside face of the section 26, as by screws 92. The block is provided witha pair of vertically spaced transverse bores 94 and 96 alignedrespectively with the ports 86 and 88, and a through-bore 98interconnecting the bores 94 and 96. O-rings 99 positioned incounterbores at the outer ends of the ports 86 and 88 elfect a sealbetween the cylinder section 26 and the valve block 18.

The vertical bore 98 in the valve block is stepped between the bores 94and 96 to receive and form a stop for a valve seat 100 slidably insertedin the bore and sealed relative thereto by O-rings 102 carried by theseat. Resting on the seat is a ball retainer 104 which traps a valveball 106 in cooperative relation wtih the seat to form therewith anupwardly opening one-way valve. Pipe plugs 108 and 110 close the upperand lower ends of the bore 98, and a spring 112 is confined between theupper plug 108 and the retainer 104 to maintain the retainer and thevalve seat in fixed positions in the bore.

The lower section 32 of the cylinder is provided adjacent its upper endwith a plurality of radial bores 114 located as close as possible to thesealing means 3536 and communicating with the port 88-96. Preferably theupper end of section 32 is necked down and the lower end of section 26is undercut to form an annular chamber assuring communication betweenthe bores 114 and the port 88-96. At its lower end, the section 32 isprovided with an external thread for detachable reception of the valve16.

The valve 16 is comprised simply of a valve seat 116, a valve ball 118and a ball retainer 120 (similar, respectively, to elements 100, 106,104) and an attaching collar 122 therefor. Preferably, the lower end ofthe section .stroke;

32 has a slight counterbore to form a shoulder or seat for the ballretainer 120, whereby to fix the assembly in the lower end of thesection upon threaded attachment of the collar122. The cylinder assembly12, or at least the lower end portions thereof, may be directly immersedin the fluid to be pumped, or a siphon hose may be connectedto thethreaded bore 124 in the collar 122, whereby said bore constitutes theinlet of the pump.

The piston in the FIGURE 1 embodiment of the invention may be formed ofone or more members comprising a relatively large diameter lower bodyportion 130 spaced from the inner periphery of the \housing sections 26and 32 and slidably engaging the inner periphery of the packing rings36, and an upper stern portion 132 of smaller diameter than the bodyportion 130 and defining therewith an upwardly facing shoulder 134. Theportion 132 of the piston extends upwardly through the bore 53 and thebore 68 in the plug 66 in limited spaced relation thereto, the sameslidably engaging the inner periphery of the packing rings 70. At itsupper end, above the cylinder assembly 12, the piston is provided with ascrew threaded end portion 76 ment thereto of a pump operating air motoror the like.

From the position illustrated in FIGURE 1, the piston may be movedupwardly by the air motor or the other drive means therefor to causecheck ball 118 .to lift from the seat 116 to permit the passage ofliquid into the lower end of the chamber 14 to substantially fill thevolume of the chamber below the piston body 130. As the piston movesdownwardly, the check valve 118 is closed and the check valve 106 isforced open by the liquid be? ing displaced by the piston body 130,whereupon liquid flows through bores 114, ports 88 and 96, bore 98 andports 94 and 86 into the upper portion of the cylinder 14 above theseals 36. The liquid so displaced fills the upper portion of the chamber14 above the piston body part 130, and the remainder of the liquiddischarged from beneath the part 130 on the downstroke of the piston isdelivered through the outlet 54. On the next upstroke of the piston, thematerial or liquid in the chamber 14 above the piston part 130 will bedelivered through the outlet because the check valve 106 is then closedand the upwardly advancing piston part 130 is decreasing the vol 'ume ofthe portion of the chamber 14 thereabove (note FIGURE 3). At the sametune, the piston is causing material to be drawn into the lower end ofthe cylinder through the inlet 124 to repeat the cycle described.

Preferably, the piston parts 130 and 132 are so dimensioned relative toone another and the cylinder that one-half of the material drawn intothe lower end of the cylinder. on each upstroke of the piston isdelivered through the outlet 54 on the next downstroke of the piston andthe other readily accomplished by making the stem part 132 of the pistonone-half the cross-sectional area of the body part 130. A specificexample is as follows:

Cylinder Cylinder section 32 Cylinder section 26 Piston part 130 Stroke5 inches.

With the above dimensions, the displacement of the piston part 130011its downstrokeis 11 cubic inches per and the displacement of theshoulder portion 134 of the piston (i.e., the area of part 130 minus thearea of part 132 multiplied by 5) equals 5.5 cubic inches per stroke.Thus, when the piston is on its downstroke, it will discharge about 11cubic inches of liquid from the lower part of chamber 14 into theby-pass 18. However, at the same time, the portion of chamber 14 abovethe piston and wrench flats 77 to facilitate .attachhalf thereof isdelivered through the r outlet on the next upstroke of the piston. Thisis most through the outlet. Thus, only 5.5 cubic inches remain to bedelivered through the outlet. Then, on the upstroke of the piston, thechamber 14 above the piston is decreased in volume by 5.5 cubic inches,and since there is no other place for the liquid to go, it will bedelivered through the outlet. Because the piston is continuouslyoperating on this 2 to 1 ratio, the result is a substantially constantfluid output from the pump.

Important features of this invention include: First, the piston issignificantly smaller than the cylinder, has clearance relative to thewalls of the cylinder and engages only the relatively flexible sealingrings 36 and 70. Second, fluid is transferred from one section of the.cylinder to the other via the valve 18, whereby no porting of any kindis required in the piston and the same may be solid. Third, the pump,due to the location of the parts 114, 86 and 94 and the valve 18, iscompletely self-purging. Fourth, the entire pump is assembled andquickly disassembled in a most expedient manner by a few screw threadedconnections. Y

The fourth feature facilitates ready replacement and adjustment of theparts subject to wear, i.e., valves 106 and 116418 and the seals 36 and70. To adjust seals .70, it is only necessary to adjust the gland nut66; and

to'replace these seals, the gland nut and the old seals are removed, newseals inserted and the nut re-applied. The seals 36 are adjusted byloosening the lock nut 44, relatively adjusting the cylinder sections 26and 32, and retightening the nut. To replace the seals, it is onlyneces-. sary to separate the sections. The balls and the seats of thevalves 16 and 18 are freely exposed for replacement simply by removingthe plug 108 and the collar 122, re spectively. Thus, even if the pumpis used with extremely abrasive and/ or corrosive materials, the fourcomponents most susceptible to wear are readily adjusted and/or replaced.

Since the cylinder 14 has no metal to metal contact with the piston 10,machining required on the two is only standard machining as opposed toprecision formation of complex surfaces, ports, etc. Thus, both mayeconomically and conveniently be made of stainless steel or any othermaterial having extremely high resistance to corrosion and/ or abrasion,even though it may be a. very difficult material to work or machine. Itis preferred to form the cylinder section 26 of square bar stock;'thenecessary length being cut from the bar, necked down at its upper end toform a mounting neck, and bored, counterbored and tapped to form thevarious bores, ports and shoulders described. The lower section 32 maybe similarly formed, or may if desired be made from commonly availablestainless steel tubing of a standard diameter.

Similarly, the piston 10 has no metal to metal contact with the cylinderassembly 12, engages only the flexible seals 36 and 70 and does notrequire any porting, valving or the like. Thus, the piston also mayeconomically and conveniently be made of extremely tough corrosion andabrasion resistant material, since it requires no complex or precisionmachining. Specifically, the piston may and preferably is solid and may,for example, be made of stainless steel or a like material. A solid rodof stainless steel may be turned or ground to define the body and stemportions and 132 and the connection portions 76 and 77, or the same maybe made of rods of different diameters (as required) welded or otherwisesecured together in coaxial relation. In either case, the rod or rodsbut even then the seals 36 and 70 are readily adjustable and/orreplaceable to compensate for the wear without detriment to the pump orits operation. In any unusual case, the piston may readily be replacedsimply by removing the valve 16 and extracting the piston. In instanceswhere the corrosive and/or abrasive action of the material is extremelysevere, even more durable materials may be utilized to form the piston10.

Specifically, referring to FIGURE 3, we have illustrated a secondembodiment of our pump wherein the piston is formed of ceramic materialloaded solely in compression, whereby even ceramic material may beutilized for high pump pressures in the order of 3,000 or more poundsper square inch. The cylinder 12 is of the same construction asillustrated in FIGURES 1 and 2, and description thereof is not repeated.The piston 10, which in essence remains of solid construction, ischaracterized by a relatively large, lower body section 130a comprisinga first ceramic tube and a relatively small upper stern portion 132acomprising a second ceramic tube. If desired, the lower tube may bemolded with an upwardly open socket guidably to receive the upper tubein coaxial relation therewith. A rod 140, preferably of stainless steel,extends through the tubes and has a flange 141 at its lower end engagingthe bottom of the lower ceramic tube and a threaded upper end 142projecting upwardly from the tubes. A nut 144 threaded onto the upperend of the rod engages the upper end of the upper ceramic tube 132a andcompressively preloads both tubes between the nut and the flange 141.The result is a composite solid piston practically impervious tocorrosion and abrasion.

Thus, all of the objects and the advantages of the invention have beenshown herein to be attained in a convenient, economical and practicalmanner.

While we have shown and described what we regard to be preferredembodiments of our invention, it will be appreciated that variouschanges, rearrangements and modifications may be made therein withoutdeparting from the scope of the invention, as defined by the appendedclaims.

We claim:

1. In a reciprocating pump: a cylinder assembly consisting essentiallyof a first cylinder member having open ends, a second cylinder memberdetachably telescoped at one end thereof into one end of said firstmember, a first seal between said ends of said first and second membersvariably compressible thereby, a third cylinder member detachablytelescoped at one end thereof into the opposite end of said firstcylinder member, a second seal of smaller diameter than said first sealbetween said ends of said first and third members variably compressiblethereby, an outlet in said first member adjacent said third member, andan inlet valve detachably mounted on the other end of said secondmember; a by-pass comprising a body detachably secured to the side wallof said first member adjacent said one end thereof and extending toopposite sides of said first seal, said first and second members andsaid body having intercommunicating ports therein establishingcommunication between immediately opposite sides of said first seal, anda one way valve in said body accommodating fluid flow from said secondmember to said first member; and a stepped solid piston reciprocable insaid cylinder members including a relatively large diameter pistonportion extending through said first seal of a smaller diameter than andreciprocable within said first and second members, and a relativelysmall diameter stem portion reciprocable in said first member andextending through said second seal and said third member; said sealsengaging longitudinally spaced portions of said piston and slidablyguiding said piston for reciprocable movement in spaced relation to thewalls of said cylinder members, said second and third members beingadjustably telescoped into said first member for independent externaladjustment of said seals.

2. In a reciprocating pump as set forth in claim 1: said members, saidbody and said valves comprising corrosion resistant machinablematerials; said piston consisting essentially of a relatively largediameter ceramic tube comprising said piston portion, a relatively smalldiameter ceramic tu'be comprising said stem portion, and a corrosionresistant tie rod extending from end to end and compressively unitingsaid ceramic tubes.

References Cited UNITED STATES PATENTS 28,012 4/1860 Ramsden 103168302,003 7/ 1884 Knorp 92258 412,942 10/1889 Babcock 103216 756,993 4/1904 Unzicker 103168 1,133,778 3/ 1915 Wrightson 92258 1,621,142 3/1927Vogel 103-168 1,751,350 3/1930 Moyer et a1. 92258 2,730,957 1/1956 Riede103153 ROBERT M. WALKER, Primary Examiner.

HENRY F. RADUAZO, Examiner.

1. IN A RECIPROCATING PUMP: A CYLINDER ASSEMBLY CONSISTING ESSENTIALLYOF A FIRST CYLINDER MEMBER HAVING OPEN ENDS, A SECOND CYLINDER MEMBERDETACHABLY TELESCOPED AT ONE END THEREOF INTO ONE END OF SAID FIRSTMEMBER, A FIRST SEAL BETWEEN SAID ENDS OF SAID FIRST AND SECOND MEMBERSVARIABLY COMPRESSIBLE THEREBY, A THIRD CYLINDER MEMBER DETACHABLYTELESCOPED AT ONE END THEREOF INTO THE OPPOSITE END OF SAID FIRSTCYLINDER MEMBER, A SECOND SEAL OF SMALLER DIAMETER THAN SAID FIRST SEALBETWEEN SAID ENDS OF SAID FIRST AND THIRD MEMBERS VARIABLY COMPRESSIBLETHEREBY, AN OUTLET IN SAID FIRST MEMBER ADJACENT SAID THIRD MEMBER, ANDAN INLET VALVE DETACHABLY MOUNTED ON THE OTHER END OF SAID SECONDMEMBER; A BY-PASS COMPRISING A BODY DETACHABLY SECURED TO THE SIDE WALLOF SAID FIRST MEMBER ADJACENT SAID ONE END THEREOF AND EXTENDING TOOPPOSITE SIDES OF SAID FIRST SEAL, SAID FIRST AND SECOND MEMBERS ANDSAID BODY HAVING INTERCOMMUNICATING PORTS THEREIN ESTABLISHINGCOMMUNICATION BETWEEN IMMEDIATELY OPPOSITE SIDES OF SAID FIRST SEAL, ANDA ONE WAY VALVE IN SAID BODY ACCOMMODATING FLUID FLOW FROM SAID SECONDMEMBER TO SAID FIRST MEMBER; AND A STEPPED SOLID PISTON RECIPROCABLE INSAID CYLINDER MEMBERS INCLUDING A RELATIVELY LARGE DIAMETER PISTONPORTION EXTENDING THROUGH SAID FIRST SEAL OF A SMALLER DIAMETER THAN ANDRECIPROCABLE WITHIN SAID FIRST AND SECOND MEMBERS, AND A RELATIVELYSMALL DIAMETER STEM PORTION RECIPROCABLE IN SAID FIRST MEMBER ANDEXTENDING THROUGH SAID SECOND SEAL AND SAID THIRD MEMBER; SAID SEALSENGAGING LONGITUDINALLY SPACED PORTIONS OF SAID PISTON AND SLIDABLYGUIDING SAID PISTON FOR RECIPROCABLE MOVEMENT IN SPACED RELATION TO THEWALLS OF SAID CYLINDER MEMBERS, SAID SECOND AND THIRD MEMBERS BEINGADJUSTABLY TELESCOPED INTO SAID FIRST MEMBER FOR INDEPENDENT EXTERNALADJUSTMENT OF SAID SEALS.